1. Field of the Invention
The present invention relates to an apparatus for and a method of reproducing audio information suitable for reproduction of, for example, music recorded on DVD, and more particularly relates to an apparatus for and a method of reproducing audio information, which can output information, such as tempo, beat or the like, recorded on DVD.
2. Description of the Related Art
For example, a disk jockey (DJ) uses two or more record players (turn tables) to then carry out continuous reproduction or remix of music at a disco or a club. The DJ sets two records (conventional analog records) in the record players, respectively, and performs the reproduction while manually operating a rotation number of each record, a timing of a rotation start and the like, and further adjusting a beat of music recorded on each record. Hereafter, such a reproduction is referred to as xe2x80x9cremix/continuous playxe2x80x9d.
Recently, the remix/continuous play has been realized by a CD or a CD reproducing apparatus. However, music is recorded on the CD as digital data, and the CD is rotated at a high speed when reproduced. Thus, in the case of the CD, differently from the analog record, it is difficult to manually operate the rotation number of the record and the timing of the rotation start. So, the remix/continuous play using the CD and the CD reproducing apparatus is performed as follows.
That is, the beat of the music is recognized from information with regard to the music itself recorded on the CD, and then a beat signal is generated in accordance with the beat. Moreover, two CD reproducing apparatuses are made synchronous with each other in accordance with this beat signal. If the music recorded on the CD has a certain rhythm and preferably includes percussion or drum sounds such as disco music or the like, a portion in which a reproduction level (volume) of the music is higher than those of the other portions can be detected as a beat (beat per measure) to thereby generate the beat signal in accordance with the detected beat. Then, the remix/continuous play can be done by making the two CD reproducing apparatuses synchronous with each other in accordance with this beat signal.
However, the method of detecting the beat per measure in accordance with the reproduction level of the music recorded on the CD has problems that it requires a complex detecting circuit and that it is difficult to detect the beat for the music in which the rhythm is not clear.
It is therefore an object of the present invention to provide an apparatus for and a method of reproducing audio information which can easily generate a beat, a tempo or the like of a music to be reproduced.
The above-mentioned object can be achieved by a first music reproducing apparatus in accordance with the present invention. The first music reproducing apparatus is an apparatus for reproducing music on the basis of music data which includes music information representing music to be reproduced and beat information representing a beat of the music and which is recorded on a recording medium. The apparatus includes: a reading device that reads the music data from the recording medium; a reproduction device that reproduces the music on the basis of the music information included in the read music data; and a beat signal output device that outputs a beat signal representing the beat of the music on the basis of the beat information included in the read music data.
In this music reproducing apparatus, the music data is read from the recording medium, and the music is reproduced on the basis of the music information included In the read music data. While the music is reproduced, the beat signal representing the beat of the reproduced music is output. Therefore, the beat of the music can be output, while the music is being reproduced.
In the first reproducing apparatus, beat strength information representing a strength of the beat of the music may be included in the music data. In this case, the first music reproducing apparatus further includes a beat strength signal output device that outputs a beat strength signal representing the strength of the beat of the music on the basis of the beat strength information included in the read music data. Accordingly, the strength of each beat can be output when the music is reproduced, or while the music is being reproduce.
In the first reproducing apparatus, tempo information representing a tempo of the music may be included in the music data. In this case, the first music reproducing apparatus further includes a tempo signal output device that outputs a tempo signal representing the tempo of the music on the basis of the tempo information included in the read music data. Accordingly, the tempo of the music can be output when the music is reproduced, or while the music is being reproduced.
The above-mentioned object can be also achieved by a second music reproducing apparatus in accordance with the present invention. The second music reproducing apparatus is an apparatus for reproducing music on the basis of music data which includes music information representing music to be reproduced and beat information representing a beat of the music and which is recorded on a recording medium. The music information is divided into a plurality of music information pieces whose time lengths are equal to each other, and the beat information is divided into a plurality of beat information pieces. Each of the beat information pieces includes information for designating one of the music information pieces in which the beat of the music is present. The second music reproducing apparatus includes: a reading device that reads the music data from the recording medium; a reproduction device that extracts the music information pieces from the read music data, and that reproduces the music on the basis of the extracted music information pieces; and a beat signal output device that extracts one of the beat information pieces from the read music data, and that designates one of the music information pieces in which the beat of music is present, and that outputs a beat signal representing the beat of the music at the same time that the designated one of the music information pieces is reproduced by the reproduction device.
In this music reproducing apparatus, the music data is read from the recording medium. Next, the music information pieces are extracted from the read music data. Next, the music is reproduced on the basis of the extracted music information pieces. While the music is being reproduced, the beat information pieces are extracted from the read music data, and one of the music information pieces in which the beat of the music is present is designated on the basis of the extracted beat information piece. Next, the beat signal representing the beat of the music is output at the same time that the designated music information piece is reproduced. Therefore, the reproduction of the music information piece in which the beat of the music is present and the output of the beat signal are simultaneously done. That is, the reproduction of the music information piece in which the beat of the music is present and the output of the beat signal are synchronized with each other.
In the second music reproducing apparatus, the beat signal output device may includes: an extraction device that extracts one of the beat information pieces from the read music data; a designation device that designates one of the music information pieces in which the beat of the music is present, on the basis of the extracted one of the beat information pieces; a calculation device that calculates a time that the designated one of the music information pieces is reproduced; a counting device that counts a time while the music is reproduced; and an output device that outputs the beat signal when the time counted by the counting device coincides with the time calculated by the calculation device.
In this beat signal output device, one of the music information pieces in which the beat of the music is preset is designated on the basis of the extracted beat information piece. Next, the time that the designated music information piece is reproduced is calculated. On the other hand, the counting device counts the time while the music is being reproduced. When the time counted by the counting device coincides with the time calculated by the calculation device, the beat signal is output. Thus, the reproduction of the music information piece in which the beat of the music is present and the output of the beat signal are simultaneously done.
In the calculating device of the beat signal output device may includes: a time identifying device that identifies a time that a first music information piece, which is placed at a lead of a row of the music information pieces, is reproduced; a time length calculation device that calculates a time length between a location of the first music information piece and a location of the designated one of the music information pieces, in the row of the music information pieces, by using the time length of each of the music information pieces; and an output time calculation device that calculates an output time of the beat signal by using the time identified by the time identifying device, and the time length calculated by the time length calculation device.
The music information pieces are arrayed in a row in order of time of reproduction. In this case, in this calculating device, the time that a first music information piece is reproduced is firstly identified. The first music information piece means the music information piece placed at a lead of a row of the music information pieces. Next, in the row of the music information pieces, a time length between the location of the first music information piece and a location of the music information piece in which the beat of the music is present is calculated by using the time length of each music information piece. Next, the output time of the beat signal is calculated by using the time that the first music information piece is reproduced, and the time length between the first music information piece and the music information piece in which the beat of the music is present. Therefore, the output time of the beat signal can be easily calculated.
In the second music reproducing apparatus, beat strength information representing a strength of the beat of the music may be included in the music data. In this case, the second music reproducing apparatus further includes a beat strength signal output device that outputs a beat strength signal representing the strength of the beat of the music on the basis of the beat strength information included in the read music data.
In the second music reproducing apparatus, tempo information representing a tempo of the music may be included in the music data. In this case, the second music reproducing apparatus further includes a tempo signal output device that outputs a tempo signal representing the tempo of the music on the basis of the tempo information included in the read music data.
The above-mentioned object can be also achieved by a music reproducing method in accordance with the present invention. The music reproducing method is a method of reproducing music on the basis of music data which includes music information representing music to be reproduced and beat information representing a beat of the music and which is recorded on a recording medium. The music reproducing method comprising the processes of: reading the music data from the recording medium; reproducing the music on the basis of the music information included in the read music data; and outputting a beat signal representing the beat of the music on the basis of the beat information included in the read music data.
In this method, beat strength information representing a strength of the beat of the music may be includes the music data in this case, the method further includes a process of outputting a beat strength signal representing the strength of the beat of the music on the basis of the beat strength information included in the read music data.
Furthermore, in this method, tempo information representing a tempo of the music may be included in the music data. In this case, the method further includes a process of outputting a tempo signal representing the tempo of the music on the basis of the tempo information included in the read music data.
The above-mentioned object can be achieved by a storage medium readable by an apparatus for reproducing music. The storage medium having a data structure which enables the apparatus to reproduce the music. The data structure has: a first group that includes music information representing music to be reproduced; and a second group that includes beat information representing a beat of the music. The music information is divided into a plurality of music information pieces whose time lengths are equal to each other. The beat information is divided into a plurality of beat information pieces. Each of the beat information pieces includes information for designating one of the music information pieces in which the beat of the music is present. Such a storage medium enables a reproducing apparatus to generate a signal representing the beat of the music and to synchronize the output of this signal and the reproduction of the music.
In the storage medium, the music information pieces may be arrayed in a row in the first group, and one of the beat information pieces may represent a time length between a location of a lead of the row of the music information pieces and a location of one of the music information pieces in which the beat of the music is present, within the first group. Such a storage medium enables a reproducing apparatus to easily identify the location of the music information piece in which the beat of the music is preset and to easily identify the output time of the signal representing the beat of the music.
In the storage medium, the second group may include beat strength information representing a strength of the beat of the music. Accordingly, the storage medium enables a reproducing apparatus to generate a signal representing a strength of each beat of the music.
Furthermore, in the storage medium, the second group may include tempo information representing a tempo of the music. Accordingly, the storage medium enables a reproducing apparatus to generate a signal representing a tempo of the music.
The nature, utility, and further feature of this invention will be more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below.